import math
x1,y1,x2,y2 = map(float, open(0).read().split())
ans = math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)
print("{:.8f}".format(ans)) import math math x1,y1,x2,y2 = map(float, open(0).read().split()) x1 map(float, open(0).read().split()) map float open(0).read().split() (0).read().split (0).read() (0).read (0) open 0 read split y1 x2 y2 ans = math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) ans math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) math.sqrt math sqrt (x1 - x2) ** 2 + (y1 - y2) ** 2 (x1 - x2) ** 2 x1 - x2 x1 x2 2 (y1 - y2) ** 2 y1 - y2 y1 y2 2 print("{:.8f}".format(ans)) print "{:.8f}".format(ans) "{:.8f}".format "{:.8f}" format ans y1,x2,y2 = map(float, open(0).read().split()) map(float, open(0).read().split()) y1 x1,y1,x2,y2 = map(float, open(0).read().split()) map(float, open(0).read().split()) x1 y2 = map(float, open(0).read().split()) map(float, open(0).read().split()) y2 ans = math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2) ans x2,y2 = map(float, open(0).read().split()) map(float, open(0).read().split()) x2
import math
x1,y1,x2,y2 = map(float, open(0).read().split())
ans = math.sqrt((x1 - x2) ** 2 + (y1 - y2) ** 2)
print("{:.8f}".format(ans))
